Food additive emulsifiers and the risk of type 2 diabetes: analysis of data from the NutriNet-Santé prospective cohort study

Background Experimental studies have suggested potential detrimental effects of emulsifiers on gut microbiota, inflammation, and metabolic perturbations. We aimed to investigate the associations between exposures to food additive emulsifiers and the risk of type 2 diabetes in a large prospective cohort of French adults. Methods We analysed data from 104 139 adults enrolled in the French NutriNet-Santé prospective cohort study from May 1, 2009, to April 26, 2023; 82 456 (79·2%) were female and the mean age was 42·7 years (SD 14·5). Dietary intakes were assessed with three 24 h dietary records collected over three non-consecutive days, every 6 months. Exposure to additive emulsifiers was evaluated through multiple food composition databases and ad-hoc laboratory assays. Associations between cumulative time-dependent exposures to food additive emulsifiers and the risk of type 2 diabetes were characterised with multivariable proportional hazards Cox models adjusted for known risk factors. The NutriNet-Santé study is registered at ClinicalTrials.gov (NCT03335644). Findings Of 104 139 participants, 1056 were diagnosed with type 2 diabetes during follow-up (mean follow-up duration 6·8 years [SD 3·7]). Intakes of the following emulsifiers were associated with an increased risk of type 2 diabetes: total carrageenans (hazard ratio [HR] 1·03 [95% CI 1·01–1·05] per increment of 100 mg per day, p<0·0001), carrageenans gum (E407; HR 1·03 [1·01–1·05] per increment of 100 mg per day, p<0·0001), tripotassium phosphate (E340; HR 1·15 [1·02–1·31] per increment of 500 mg per day, p=0·023), acetyl tartaric acid esters of monoglycerides and diglycerides of fatty acids (E472e; HR 1·04 [1·00–1·08] per increment of 100 mg per day, p=0·042), sodium citrate (E331; HR 1·04 [1·01–1·07] per increment of 500 mg per day, p=0·0080), guar gum (E412; HR 1·11 [1·06–1·17] per increment of 500 mg per day, p<0·0001), gum arabic (E414; HR 1·03 [1·01–1·05] per increment of 1000 mg per day, p=0·013), and xanthan gum (E415, HR 1·08 [1·02–1·14] per increment of 500 mg per day, p=0·013). Interpretation We found direct associations between the risk of type 2 diabetes and exposures to various food additive emulsifiers widely used in industrial foods, in a large prospective cohort of French adults. Further research is needed to prompt re-evaluation of regulations governing the use of additive emulsifiers in the food industry for better consumer protection. Funding European Research Council, French National Cancer Institute, French Ministry of Health, IdEx Université de Paris, and Bettencourt-Schueller Foundation.